no me guarda los checkbox en la bd

[newprogram]

Tengo un problema al insertar los checkbox en la bd solo me guarda comillas :S


!codigo html¡

<fieldset >
</br>
<div id="grupo1" align="left">
<label ><span>*</span>NPDVSA&nbsp;&nbsp;&nbsp;</label>
<input type="text" name="npdvsa" class="obligatorio" required><br ><br > <br>

<label><span>*</span> Modelo&nbsp;&nbsp;&nbsp;&nbsp; </label>
<select name="modelo" class="obligatorio"required >
<option value="cheyenne">CHEYENNE</option>
<option value="gran vitara">GRAN VITARA</option>
<option value"luv">LUV</option>
<option value"machito">MACHITO</option>
<option value"titan">TITAN</option>
</select>
<br ><br > <br>
<label><span>*</span>Año&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;</label>
<select name="año" class="obligatorio" required>
<option>2000</option></label>
</select>

<br><br><br>
<label ><span>*</span>Condicion&nbsp;</label>
<select name="condicion" class="obligatorio"required >
<option value="">Seleccionar --></option>
<option value="activa">Activa</option>
<option value="inactiva" >Inactiva</option>
<option value="taller" >Taller</option>
<option value="desincorporada" >Desincorporada</option>
</select>
</div >
<div id="grupo004" align="left">
<label ><span>*</span>Placa&nbsp;&nbsp;</label>
<input type="text" name="placa" class="obligatorio" required><br ><br > <br>

<label ><span>*</span>Color&nbsp;&nbsp;</label>
<input type="text" name="color" class="obligatorio"required ><br ><br > <br>

<label ><span>*</span>Tipo&nbsp;&nbsp;&nbsp;&nbsp;</label>
<select name="tipo" class="obligatorio"required>
<option value="">Seleccionar --></option>
<option value="camioneta" >Camioneta</option>
<option value="pick-up" >Pick-up (Sensilla)</option>
<option value="rustico" >Rustico</option>
<option value="sportage">Sportage</option>
<option value="sport wagon">Sport Wagon</option>
<option value="sportage-kia">Sportage-Kia</option>
</select><br ><br > <br>
</div>

<div id="grupo3" align="left">

<label ><span>*</span>Marca&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbs p;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</label>
<select name="marca" class="obligatorio" required> <br ><br > <br>
<option value="chevrolet">CHEVROLET</option>
<option value="kia">KIA</option>
<option value="nissan">NISSAN </option>
<option value="toyota">TOYOTA</option>
</select><br><br><br>

<label ><span>*</span>Kilometraje&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</label>
<input type="text" name="kilometraje" class="obligatorio" required><br ><br > <br>

<label ><span>*</span>Estado&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nb sp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</label>
<select name="estado" class="obligatorio"required>
<option >Seleccionar --></option>
<option value="bueno" >Bueno</option>
<option value="regular">Regular</option>
<option value="malo">Malo</option>
</select><br ><br > <br > <br > <br >
</div>
</fieldset>
<h4 class="titulo">Accesorios</h4>

<fieldset >
<br>
<div id="grupo4" align="left">
<input name="cdrepuesto" type="checkbox" value="1" >Caucho de Repuesto<br ><br >
<input name="poliza" type="checkbox" value="2">Poliza <br ><br >
<input name="co" type="checkbox" value="3" >Certificado de Origen</div>
<div id="grupo5" align="left">
<input name="llavrueda " type="checkbox" value="4">Extintor<br ><br >
<input name="extintor" type="checkbox" value="5">Extintor<br ><br >
<input name="gato" type="checkbox" value="6" >Gato<br ><br >
</div>
<div id="grupo6" align="left">
<label ><span>*</span>Serial Motor&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</label>
<input type="text" name="sm" class="obligatorio"required > <br ><br >
<label><span>*</span>Serial Carroceria</label>
<input type="text" name="sc" class="obligatorio"required ><br ><br ><br >
</div>
</fieldset>

!codigo php¡
$npdvsa= $_POST['npdvsa'];
$placa= $_POST['placa'];
$marca= $_POST['marca'];
$modelo= $_POST['modelo'];
$color= $_POST['color'];
$km= $_POST['kilometraje'];
$año= $_POST['año'];
$tipo= $_POST['tipo'];
$crepst=$_POST['cdrepuesto'];
$polz=$_POST['poliza'];
$corigen=$_POST['co'];
$lrueda_=$_POST['llavrueda'];
$estado= $_POST['estado'];
$condi= $_POST['condicion'];
$ext=$_POST['extintor'];
$gto=$_POST['gato'];
$smotor= $_POST['sm'];
$srcarro= $_POST['sc'];
$busqueda= pg_query("SELECT tx_npdvsa
FROM c003t_vehiculos WHERE tx_npdvsa='$npdvsa'");

if(pg_num_rows($busqueda)>0)
{
echo "<script>";
echo "alert('¡El NPDVSA Ya Está Asignada A Otro Vehiculo!');";
echo 'history.back();';
echo "</script>";
}
else
{
pg_query("insert into c003t_vehiculos(tx_npdvsa,tx_placa,tx_marca,tx_mod elo,tx_color,nu_kilometraje,nu_año,tx_tipo,tx_esta do,tx_condicion,in_caucho_repuesto,in_llave_de_rue da,tx_serial_motor,in_poliza,in_extintor,tx_seriac arroceria,in_gato,in_certificado_origen)values('$n pdvsa','$placa','$marca','$modelo','$color',$km,$a ño,'$tipo','$estado','$condi','$crepst','$lrueda', $smotor,'$poliz','$ext',$srcarro,'$gto','$corigen' ");
pg_close($con);
echo "<script>";
echo "alert('Vehiculo Registrado con Exito');";
echo "</script>";
}